Integrated electronic circuits often have drivers at the outputs to drive current through external devices. For example, integrated circuits used to illuminate light emitting diodes (LEDS) may use a driver at the output of the integrated circuit which sinks electrical current from the LEDS to turn them on. However, the drivers at the outputs of integrated circuits are particularly sensitive to damage from electrostatic discharge, or ESD, because they are connected immediately inside the outputs of the integrated circuit and are therefore exposed to high electrical voltage and resultant currents caused by ESD. Integrated circuits are particularly vulnerable to ESD before they are soldered or otherwise electrically connected to a circuit board with ground and power rails. The voltage in an ESD strike can be as high as thousands of volts, even from a static discharge from a persons touch. Although the current from such an ESD strike may be relatively low, without ESD protection for the driver the transistors in the driver may be destroyed.
One solution used to protect drivers from ESD strikes is to include an ESD protection cell at the output transistor of the driver. The ESD protection cell reacts more quickly than the output transistor, dissipating current from the ESD strike through the ESD protection cell before it can damage the output transistor. However, for a high voltage output driver, the ESD protection cell must be undesirably large and is therefore not an ideal solution.